33 research outputs found
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Integration of vision and force sensors for grasping
This paper describes a set of methods that can be used to integrate real-time external vision sensing with internal force and position sensing to estimate contact forces by the fingers of a hand. Estimating these forces and contacts is essential to performing dextrous manipulation tasks. Most robotic hands are either sensorless or lack the ability to accurately and robustly report position and force information relating to contact. By adding external vision sensing, we can complement any internal sensors to more accurately estimate forces and contact positions. Experiments are described that use real-time visual trackers in conjunction with internal strain gauges and a new tactile sensor to accurately estimate finger contacts and applied forces for a three fingered robotic hand
RCW 86: A Type Ia Supernova in a Wind-Blown Bubble
We report results from a multi-wavelength analysis of the Galactic SNR RCW
86, the proposed remnant of the supernova of 185 A.D. We report new infrared
observations from {\it Spitzer} and {\it WISE}, where the entire shell is
detected at 24 and 22 m. We fit the infrared flux ratios with models of
collisionally heated ambient dust, finding post-shock gas densities in the
non-radiative shocks of 2.4 and 2.0 cm in the SW and NW portions of the
remnant, respectively. The Balmer-dominated shocks around the periphery of the
shell, large amount of iron in the X-ray emitting ejecta, and lack of a compact
remnant support a Type Ia origin for this remnant. From hydrodynamic
simulations, the observed characteristics of RCW 86 are successfully reproduced
by an off-center explosion in a low-density cavity carved by the progenitor
system. This would make RCW 86 the first known case of a Type Ia supernova in a
wind-blown bubble. The fast shocks ( km s) observed in the NE
are propagating in the low-density bubble, where the shock is just beginning to
encounter the shell, while the slower shocks elsewhere have already encountered
the bubble wall. The diffuse nature of the synchrotron emission in the SW and
NW is due to electrons that were accelerated early in the lifetime of the
remnant, when the shock was still in the bubble. Electrons in a bubble could
produce gamma-rays by inverse-Compton scattering. The wind-blown bubble
scenario requires a single-degenerate progenitor, which should leave behind a
companion star.Comment: Accepted for publication in ApJ. 50 pages, 9 figure
The Detailed Optical light Curve of GRB 030329
We present densely sampled BVRI light curves of the optical transient associated with the gamma-ray burst (GRB) 030329, the result of a coordinated observing campaign conducted at five observatories. Augmented with published observations of this GRB, theY. M.
Lipkin and E. O. Ofek are grateful to the Dan-David prize
foundation for financial support. A. Gal-Yam acknowledges
a Colton Fellowship. Y. M. Lipkin, E. O. Ofek, A. Gal-Yam,
D. Poznanski, and D. Polishook were supported in part
by grants from the Israel Science Foundation
Admixture Mapping of 15,280 African Americans Identifies Obesity Susceptibility Loci on Chromosomes 5 and X
The prevalence of obesity (body mass index (BMI) ≥30 kg/m2) is higher in African Americans than in European Americans, even after adjustment for socioeconomic factors, suggesting that genetic factors may explain some of the difference. To identify genetic loci influencing BMI, we carried out a pooled analysis of genome-wide admixture mapping scans in 15,280 African Americans from 14 epidemiologic studies. Samples were genotyped at a median of 1,411 ancestry-informative markers. After adjusting for age, sex, and study, BMI was analyzed both as a dichotomized (top 20% versus bottom 20%) and a continuous trait. We found that a higher percentage of European ancestry was significantly correlated with lower BMI (ρ = −0.042, P = 1.6×10−7). In the dichotomized analysis, we detected two loci on chromosome X as associated with increased African ancestry: the first at Xq25 (locus-specific LOD = 5.94; genome-wide score = 3.22; case-control Z = −3.94); and the second at Xq13.1 (locus-specific LOD = 2.22; case-control Z = −4.62). Quantitative analysis identified a third locus at 5q13.3 where higher BMI was highly significantly associated with greater European ancestry (locus-specific LOD = 6.27; genome-wide score = 3.46). Further mapping studies with dense sets of markers will be necessary to identify the alleles in these regions of chromosomes X and 5 that may be associated with variation in BMI
A 'snip' in time: what is the best age to circumcise?
<p>Abstract</p> <p>Background</p> <p>Circumcision is a common procedure, but regional and societal attitudes differ on whether there is a need for a male to be circumcised and, if so, at what age. This is an important issue for many parents, but also pediatricians, other doctors, policy makers, public health authorities, medical bodies, and males themselves.</p> <p>Discussion</p> <p>We show here that infancy is an optimal time for clinical circumcision because an infant's low mobility facilitates the use of local anesthesia, sutures are not required, healing is quick, cosmetic outcome is usually excellent, costs are minimal, and complications are uncommon. The benefits of infant circumcision include prevention of urinary tract infections (a cause of renal scarring), reduction in risk of inflammatory foreskin conditions such as balanoposthitis, foreskin injuries, phimosis and paraphimosis. When the boy later becomes sexually active he has substantial protection against risk of HIV and other viral sexually transmitted infections such as genital herpes and oncogenic human papillomavirus, as well as penile cancer. The risk of cervical cancer in his female partner(s) is also reduced. Circumcision in adolescence or adulthood may evoke a fear of pain, penile damage or reduced sexual pleasure, even though unfounded. Time off work or school will be needed, cost is much greater, as are risks of complications, healing is slower, and stitches or tissue glue must be used.</p> <p>Summary</p> <p>Infant circumcision is safe, simple, convenient and cost-effective. The available evidence strongly supports infancy as the optimal time for circumcision.</p
Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses
To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely
Using Tactile and Visual Sensing with a Robotic Hand
Most robotic hands are either sensorless or lack the ability to accurately and robustly report position and force information relating to contact. This paper describes a robotic hand system that uses a limited set of native joint position and force sensing along with custom designed tactile sensors and real-time vision modules to accurately compute finger contacts and applied forces for grasping tasks. Three experiments are described: integration of real-time visual trackers in conjunction with internal strain gauge sensing to correctly localize and compute finger forces, determination of contact points on the inner and outer links of a finger through tactile sensing and visual sensing, and determination of vertical displacementby tactile sensing for a grasping task